Capacitive, ceramic pressure sensor
Application
Pressure sensor for use in the pressure measurement of liquidand gaseous media.
Your benefits
Dry capacitive ceramic sensor with ultrapure (99.9 %) Al2O3 ceramic
• High overload resistance
• Very good long-term stability
• High corrosion resistance
• Digital/analog signal output (SPI, UART, U)
• Measuring ranges from 0 to 0.1 bar (0 to 1.5 psi) to 0 to 100 bar (0 to 1500 psi)
• Optional temperature output, switch output
Function and system design
Measuring principle
A capacitive ceramic sensor element is at the core of the USC30. The basic material is (Al2O3), an ultrapure (99,9%) aluminum oxide ceramic that is highly resistant to many aggressive gases and liquids.Two cylindrical ceramic components (process isolating diaphragm and meter body) are hermeticallysealed together. In the case of absolute pressure sensors, the reference vacuum of 3,0 x 10-6 mbar thatis generated in the production process between the process isolating diaphragm and the meter bodybecomes permanent, thereby enabling precise pressure measurement relative to the vacuum. In thecase of gauge pressure sensors, the back of the process isolating diaphragm is aerated, i.e. this sensormeasures the gauge pressure relative to the atmospheric pressure. In electrical terms, the sensor element represents a plate capacitor whose change in capacitance is ameasure for the change in pressure. The capacitive measurement method satisfies the highestrequirements with regard to resolution and reproducibility. Together with the hysteresis-free behaviorof the Al2O3 material, it forms the basis for the excellent technical specifications of the pressure sensor.Furthermore, the sensor element is a dry measuring cell, i.e. there is no separating diaphragm or oilfilling which could influence the measurement. Another advantage of the capacitive ceramic sensor isits high overload resistance.
Input
Measured process variable
• Gauge pressure or absolute pressure
• Temperature
